Athletic is a skill in The Sims 3. Sims with the Athletic trait gain the skill faster. Athletic Sims enjoy working out, and get a cool vibe when they are at the gym. Most Athletic Sims will aspire to work out, or to become a professional athlete. Athletic Sims can also train others, and enjoy talking about Athletics with other Sims.
Body Builders have dedicated at least 60 hours to strength workouts. This dedication pays off, because they are never fatigued after strength workouts.
Marathon Runner
Marathon Runners must run at least 500 kilometers before they earn the title. However, accomplishing this incredible feat guarantees them a longer, healthier life.
Fitness Nut
Fitness Nuts have spent 75 hours focusing on cardio workouts. All that time experiencing the burn means they are no longer fatigued after cardio workouts.
Since Generations or patch 1.22, children no longer gain Athletic skill. They will instead learn the hidden Child Athletic skill up to level 3, which will transfer into Athletic skill once they grow up to teenagers.
With Showtime, teenagers who start raising Athletic skill will make the Master Acrobat lifetime wish appear.
Athletic skill also determines the success rate of physical fights when two Sims are in poor social standings with each other. In general, the Sim with the higher Athletic skill is more likely to win the fight. Completing the Body Builder skill challenge also adds a bonus to the chance for a Sim to come out on top at the end of a fight.
Sim with high skill point can run faster than sim with lower skill point.